There is no book quite like it, says Ashley J. Tellis of this seminal work on the Lashkar-e-Taiba (LeT) by Indian strategic expert Wilson John. He could not have been more on the spot. This gripping book should be made a must read globally, including in Pakistan, where the terrorist outfit, John tells us, has enjoyed the active support of civil society as well as military and intelligence agencies.

John debunks the theory that LeT, which carried out the audacious and murderous Mumbai terrorist attack in 2008, is a so-called non-state actor. It may be so but only in name.

For all practical purposes, this is an extended arm of the Pakistani state, enjoying the strong backing of Inter-Services Intelligence (ISI), with deep roots in Punjab, the country's political and military heartland.

It is silly to think that ISI officers in league with LeT are 'rogues'. 'They are all 'regular' officers pretending to be 'rogues'.' No wonder that trainers in LeT camps are retired or serving military personnel.

The book provides a comprehensive insight into LeT, covering a wide sweep - from its birth to ballooning growth, close ties with Islamabad/Rawalpindi, its vast terrorist producing factories, global threat and links with Al Qaeda, its sleeper agents, as well as its colossal cadre and financial strength.

Based on both published literature and other documents, John estimates that LeT has trained since the late 1990s a staggering half a million men and women to carry out an armed struggle. Of this, about 50,000, comparable to an army division, are on active duty while the others act as reserves, ready to fight for Pakistan, if need be, against India.

Until recently, there has been considerable ambiguity and ignorance in the West about LeT. The perception began to change from the time US commandos raided Pakistan and shot dead Osama bin Laden, exposing, as never before, the duplicitous relationship the Pakistani state has had with the US (while taking its money) and the Islamists, including Al Qaeda.

So although LeT trained its eyes and guns on India, it is 'not driven by any domestic agenda or grievances but a broader Islamist one of establishing an Islamic Caliphate through jehad'.

What do you do with a terrorist group that has the backing of a state wedded to terrorism as an instrument of state policy, an outfit which at one point had about 2,500 offices in Pakistan, has operated in 22 countries, shown capabilities comparable only to state-backed intelligence agencies, and which has provided training to a large number of foreigners ranging from Chechens and Uzbeks to Germans, Britons and French to Algerians, Indonesians, Bangladeshis, Afghans and Indians?

John answers the question without mincing words: the threat posed by LeT to peace and stability in the world has never been more serious than now. And he makes another, related point: LeT needs to be destroyed. Now!